Month: January 2008

It’s not often a children’s book on hallucinogenic drugs gets written, but this seems to be one of those occasions. Matt Hutson has scanned in some remarkable pages from exactly such a book, published in 1991.

Apparently it’s quite comprehensive, covering everything from neurons to shamans, and is also full of funky illustrations.

The prose is lucid, but the pictures crack me up. Take the cover. Look kids, in a drug free zone, you can do all kinds of things, like play tic-tac-toe. Or even watch people play tic-tac-toe! And remember, friends don’t let friends wear non-footie pants.

In some cases the book might be counterproductive: “Have you ever looked at yourself in an amusement park mirror? Look what happened to you! Now, try to imagine that the whole world looked that way to you.” Awesome! Where can I get some?

The Economistcovers an intriguing study that found the financial success of a company can be largely guessed by making a judgement based on photographs of the chief executives.

Most interestingly, the people doing the guessing weren’t particularly skilled in business or finance, they were undergraduate student volunteers.

And Dr Ambady and Mr Rule were surprised by just how accurate the students’ observations were. The results of their study, which are about to be published in Psychological Science, show that both the students’ assessments of the leadership potential of the bosses and their ratings for the traits of competence, dominance and facial maturity were significantly related to a company’s profits. Moreover, the researchers discovered that these two connections were independent of each other. When they controlled for the ‚Äúpower‚Äù traits, they still found the link between perceived leadership and profit, and when they controlled for leadership they still found the link between profit and power.

These findings suggest that instant judgments by the ignorant (nobody even recognised Warren Buffett) are more accurate than assessments made by well-informed professionals. It looks as if knowing a chief executive disrupts the ability to judge his performance.

Other studies have looked at whether it is possible to judge the success of politicians from their photographs.

Perhaps sadly, it seems it is possible. A study [pdf] published in Evolution and Human Behavior found that face shape could reliably predict voter preference in nine leadership elections from four countries – Australia, New Zealand, the UK, and the USA.

A study just published in the Proceedings of the National Academy of Sciences found that photograph-only judgements of competence could also predict the winners in election for US state governor, even when they were flashed on-screen for less than a quarter of a second.

Interestingly, showing people the faces for longer actually changed people’s competency ratings and reduced how well these judgements predicted the election winners.

Memoirs of a Postgrad has got a great write-up of a new low-power MRI machine, the technology that does most of the structural and functional brain scans. Even the smaller MRI machines need huge electromagnets, but this new technology uses magnets thirty thousand times weaker to image the brain.

In a standard MRI machine, a strong magnetic field is used to align the proton in each of the hydrogen atoms before using an RF pulse to knock them out of alignment. As they snap back into alignment with the magnetic field, they emit a signal which can be detected and used to create a 3D image. In the new version, the very small magnetic field isn’t enough to align the protons, so a short duration (1 second) magnetic pulse of slightly higher magnitude (30 millitesla).

The resulting signals are very small, so an array of highly sensitive magnetometers are used (so-called superconducting quantum interference devices, or SQUIDS). A hugely important additional advantage of using these SQUIDS is that they are also used in the MEG (magnetoencephalography) imaging technique. This potential for MRI and MEG using the same machine raises the intriguing possibility of producing simultaneous structural images (using the MRI) and brain activation maps (using the MEG).

Unfortunately, the use of SQUIDs dashes any hopes of making the machines much smaller.

The SQUID sensors need to be extremely cold (working at approximately -170 degrees C) and so are usually bathed in liquid nitrogen, meaning a huge insulated tank sits atop the scan area.

IEEE Spectrum magazine has an article with some images from the new type of scanner, which look pretty fuzzy at the moment, but apparently can better distinguish tumours in the brain and will undoubtedly become clearer as new software is developed.

It was 1970, and a white Rolls Royce was gliding through the streets of London. Inside were the obviously disturbed Roman Polanski, the film director still reeling from the murder of his wife, and Richard Gregory, the legendary cognitive psychologist.

Polanski had discovered Gregory’s work on visual perception through his bookEye and Brain and decided he wanted to enlist Gregory’s help to create a 3D horror movie.

The movie was intended to be revolutionary, taking advantage of the brain’s perceptual quirks to make a truly disturbing visual experience.

They spent the week in Polanski’s office, actually the rear of his white Rolls Royce, discussing concepts, checking out studios and making plans.

In the end, their plans were too ambitious and were abandoned by Polanksi, who moved on to other projects.

Gregory remembers the episode well however, and discusses his meeting with Polanski, and the science behind their abandoned project, in an online audio recording.

Interestingly, Gregory also mentions that Polanksi also wanted to use the techniques they developed to make a 3D erotic movie.

Visual perception lectures would have never been the same again, much to the delight of generations of psychology students, but sadly, it remains only as a wonderful tale of an unlikely pairing.

The recording seems to be from a fantastic Polanski DVD box set that also contains his filmRepulsion, notable for its portrayal of a young woman’s descent into a terrifying psychosis and the film’s use of perceptual distortion to communicate the experience to the viewer.

ABC Radio National’s opinion programme Ockham’s Razor has an engrossing edition on how our perception and ownership of our body can break down after brain injury – leading to disorders where we think our limbs are someone else’s, where we feel there’s a phantom body behind us, or where we think we’ve been cloned.

The talk is by neuropsychologist John Bradshaw who specialises in understanding how the body is represented by the brain, including the experience of having feelings from an amputated phantom limb.

The talk is a little dense in places but more than worth the attention it needs, as the somewhat wordy sentences unpack into an evocative tour through the far reaches of some strikingly neurological syndromes.

One of the most unusual of these disorders is somatoparaphrenia.

While limb paralysis is not unusual after brain injury, in somatoparaphrenia the patient denies the limb is their own and often suggests that it is someone else’s, such as their husband’s, their doctor’s, or even a ‘dead’ limb that has been attached by people trying to trick them.

One of the earliest discussions of these phenomenon is in a 1955 paper on the personification of paralysed limbs. Rather wonderfully, the full text of the paper is available online.

Link to Ockham’s Razor on bodily integration, identity and brain injury.Link to paper ‘Personification of Paralysed Limbs in Hemiplegics’.

Bad Science has a fantastic article on antidepressants and the widely-promoted but scientifically unsupported ‘low serotonin theory’ of depression.

Owing to a huge advertising push by drug companies, not only the ‘man on the street’, but also a surprisingly large numbers of mental health professionals (clinical psychologists, I’m look at you) believe that depression is linked to ‘low serotonin’ in the brain.

The only drawback to this neat sounding theory is that it is almost completely unsupported by empirical evidence or scientific studies.

Experiments that have deliberately lowered serotonin levels in the brain have found that it is possible to induce ‘negative mood states’ (usually milder and as short-lasting as a slight hangover), but these do not even begin to compare to the depths of clinical depression.

In terms of patients with the clinical mood disorder itself, not a single study has found a link to reduced serotonin.

Bad Science neatly reviews the science, and also discusses a new research study which chased up journalists that propagated the myth to ask for their sources.

Needless to say, none of them had any sound scientific basis for their claims.

This is not to say that antidepressants don’t help treat depression, (evidence suggests they do – although the effect is more modest than drug companies would have us believe), or that neurobiology isn’t important (by definition, if it’s a change in thought and mood, it’s a change in brain function).

If you’re interested in the history of how the ‘low serotonin hypothesis’ came to be thought up and then subsequently promoted, despite the lack of evidence, Professional Psychology: Research and Practice recently published a great article on the topic [pdf].

Link to Bad Science on the serotonin myth.pdf of article on the history and popularity of the myth.Link to excellent PLoS Medicine article on evidence and adverts.